KR101064228B1 - Lead-free glass frit composition for use in sealing - Google Patents

Abstract

The present invention is substantially free of lead (Pb) and 80 to 95% by weight of glass frit containing 32 to 42 mol% of Bi ₂ O ₃ , 25 to 35 mol% of ZnO and 22 to 28 mol% of B ₂ O ₃ and in the rod wear lead-free glass frit composition comprising a low-expansion ceramic filler, 5 to 20% by weight, the glass frit is, SiO ₂ 0.5 ~ further comprising a 5 mol%, and Li ₂ O, Na ₂ O, K ₂ O and 0.5 to 5 mol% of one or more alkali metal oxides selected from Cs ₂ O, and 0.5 to 4 mol% of one or more transition metal oxides selected from CoO, CuO, NiO, and MnO. A lead-free glass frit composition for sealing a flat panel display panel, wherein a sintered glass frit at 520 ° C. does not generate a crystal phase and can be sealed at a lower temperature and has a lower coefficient of thermal expansion (VFD). , PDP, FED and the like).

Sealed, glass frit, lead free, flat panel display panel

Description

Lead-free glass frit composition for use in sealing}

The present invention relates to a glass frit composition for sealing.

Existing sealing compositions are mainly composed of PbO-B ₂ O ₃ -SiO ₂ -based glass frit containing Pb (lead), and PbTiO ₃ containing ceramic filler and Pb is mainly used. Recently, the Pb (lead) component causes pollution to the soil or water quality, the situation is used worldwide. Therefore, studies on lead-free glass frit compositions for sealing substantially free of Pb (lead) have been actively conducted.

Korean Patent Publication No. 2003-0057344 discloses SnO 30-70 mol%, P ₂ O ₅ 20-45 mol%, La ₂ O ₃ 0.1-25 mol%, RO (R is Zn, Mg) 0-20 mol%, Al ₂ O ₃ 0-10 mol%, SiO ₂ 0-15 mol%, B ₂ O ₃ 0-30 mol%, R ' ₂ O (R' is Li, Na, K, Cs) 0-20 mol% Tin phosphate-based glass that does not contain lead components that can be sealed at low temperatures and composite materials using the same, Korean Patent Publication No. 2005-0105167 discloses 20 to 80% by weight of B ₂ O ₃ / V ₂ O ₅ and 0 to 60% by weight of ZnO. %, BaO 0 to 80% by weight lead-free glass material for sealing and sealing products and sealing method using the same, Korean Patent Publication No. 2006-0116171, V ₂ O ₅ 10 ~ 60 mol%, P ₂ O ₅ 5 ~ 40 mol%, Bi ₂ O ₃ 1-30 mol%, TeO ₂ 0-40 mol%, R ' ₂ O (R' is Li, Na, K, Cs) 0-20 mol%, RO (R is Mg, Ca, Sr, Ba) Vanadium phosphate-based glass composed of 0 to 30 mol%, P ₂ O ₅ 25 to 50 mol%, SnO: ZnO molar ratio of 1: 1 to 5: 1 in Korea Patent Publication No. 1997-0000898 Lead-free glass and its products consisting essentially of SnO and ZnO, KR10-2005-0038472 Standing BaO 5 ~ 40 wt%, ZnO 5 ~ 40 _{wt%, B 2 O 3 10 ~} 40 _{wt%, V 2 O 5 5 ~} 45 wt.%, R ₂ O ₃ (R is As, Sb) 5 ~ 45 wt. %, SiO ₂ or a method for producing a low melting lead-free frit glass composed of 5 to 32% by weight of alkali-free waste glass, Korean Patent Laid-Open No. 2006-0032950 discloses 4 of V ₂ O ₅ , ZnO, BaO, P ₂ O ₅ The lead-free glass material for sealing processing which contains a metal oxide of a species as an essential component, the sealing processed material, and the sealing processing method using the same are disclosed. In addition, Korean Patent Publication No. 2003-0010415 discloses 60 to 75 wt% of Bi ₂ O ₃ , 7 to 15 wt% of B ₂ O ₃ , 5 to 7 wt% of SiO ₂ , 1 to 18 wt% of P ₂ O ₅ , and Al. ₂ O ₃ 1 ~ _3% by weight, ZnO 2 ~ 7 wt%, BaO 1 ~ 3 weight%, TiO ₂ 0 ~ lead-free non-alkali consisting of 2% by weight of low-melting glass, Korea Patent Publication No. 2007-0006711 discloses a Bi ₂ O ₃ 70 ~ 85 _{wt%, B 2 O 3 4.5 ~} 10 wt%, ZnO 8 ~ 20 wt%, Al ₂ O ₃ 0.1 ~ the rod wear compositions, Korea Patent No. 0653408 No. consisting of 1 wt.% Bi ₂ O ₃ Disclosed is a lead-free frit composition for sealing a flat panel display panel composed of 30 to 45 mol%, 13 to 35 mol% of ZnO, and 20 to 35 mol% of B ₂ O _3, and a paste composition including the frit.

Among these compositions, P ₂ O ₅ -SnO / ZnO-based glass frit can be sealed at low temperature, but its chemical durability is weak and it is non-uniformly sealed at the time of secondary sealing because SnO of glass frit is reduced to Sn metal during burnout of binder during primary sintering. In addition, there is a weak point of the adhesion between the glass and the glass, BaO-ZnO-B ₂ O ₃ glass frit also has a weak chemical durability, there is a limit to low temperature sealing, Bi ₂ O ₃ system mainly from the viewpoint of chemical durability It is being studied with glass frit.

However, since the Bi ₂ O ₃ -based glass frit is used for sealing a flat panel display panel, the glass frit itself is determined to at least 520 ° C. since the first sintering of the internal phosphor composition and the sealing composition is performed simultaneously for the process and cost reduction. These compositions should not be precipitated, but the above compositions cause partial crystals to be precipitated, causing the partial crystal parts not to re-melt during secondary low temperature (500 ° C or less) sealing firing, resulting in uneven sealing, which shortens the life span of the flat panel display panel. . In addition, simultaneous sintering with the phosphor composition below 520 ° C. results in poor contrast due to the presence of carbon in the flat panel display panel due to the remaining binder in the phosphor composition.

Accordingly, the present invention solves the problems of the conventional lead-free glass frit composition for sealing, and does not contain Pb (lead), and is a sealing composition that can be simultaneously sintered at 520 ° C. with a phosphor composition and at a lower temperature. The coefficient of thermal expansion also provides for a smaller sealing composition. Specifically, the primary sintering temperature is 520 ° C, the secondary sealing temperature is 490 ° C or less, or preferably 450 ° C or less and the thermal expansion coefficient is to provide a glass frit composition for sealing of 82 × 10 ^-7 / ° C or less. .

The lead-free glass frit composition for sealing a flat panel display panel of the present invention is substantially free of lead (Pb) and 32 to 42 mol% of Bi ₂ O ₃ , 25 to 35 mol% of ZnO and 22 to 28 mol% of B ₂ O _3. In the sealing lead-free glass frit composition comprising 80 to 95% by weight of glass frit and 5 to 20% by weight of low-expansion ceramic filler, the glass frit further comprises 0.5 to 5 mol% of SiO ₂ , Li 0.5 to 5 mol% of one or more alkali metal oxides selected from ₂ O, Na ₂ O, K ₂ O, and Cs ₂ O, and 0.5 to 5 mol% of one or more transition metal oxides selected from CoO, CuO, NiO, and MnO. It further comprises 4 mol%.

In the lead-free glass frit composition for sealing a flat panel display panel of the present invention, the molar ratio of the alkali metal oxide and the transition metal oxide is characterized in that 1: 1 to 3: 1.

In the lead-free glass frit composition for sealing a flat panel display panel of the present invention, the sum of the alkali metal oxide and the transition metal oxide is 3 to 6 mol%.

In the lead-free glass frit composition for sealing a flat panel display panel of the present invention, the glass frit is characterized in that it further comprises 0.1-6 mol% BaO or 0.1-5 mol% Al ₂ O ₃ .

In the lead-free glass frit composition for sealing a flat panel display panel of the present invention, the glass frit is characterized in that no crystal is precipitated when sintered at 520 ° C.

The lead-free glass frit composition for sealing a flat panel display panel of the present invention is capable of co-firing at a phosphor composition and 520 ° C. or less, preferably 500 to 520 ° C., more preferably 510 to 520 ° C., and most preferably 515 to 520 ° C. It is characterized by.

The lead-free glass frit composition for sealing a flat panel display panel of the present invention is characterized by being sealed at 490 ° C. or less, preferably 470 ° C. or less, more preferably 450 ° C. or less, and most preferably 430 to 450 ° C.

In the lead-free glass frit composition for sealing a flat panel display panel of the present invention, the low-expansion ceramic filler is characterized in that at least one selected from cordierite and zircon.

The lead-free glass frit composition for sealing a flat panel display panel of the present invention has a value of thermal expansion coefficient in the range of 70 to 82 × 10 ⁻⁷ / ° C., preferably 70 to 80 × 10 ⁻⁷ / ° C., more preferably at 30 to 300 ° C. Is characterized in that 75 ~ 80 × 10 ^-7 / ℃.

In the conventional lead-free sealing composition, crystals are precipitated at less than 520 ° C., so that the simultaneous sintering of the sealing composition and the phosphor composition is difficult, and therefore, simultaneous firing is performed at 510 ° C. or lower to reduce production cost due to process shortening. However, the binder in the phosphor composition is completely burned out at about 520 ℃, co-fired at 510 ℃ or less, the binder remains. This shortens the contrast and lifespan due to the remaining of the phosphor composition binder inside the flat panel display panel.

Therefore, the lead-free glass frit composition for sealing according to the present invention solves this problem and has a low transition temperature and softening temperature of glass to enable low temperature sealing, and has excellent flow button (Flow Button) characteristics without crystal precipitation at 520 ° C. By providing the composition, there is provided a lead-free glass frit composition for sealing a flat panel display panel excellent in durability and reliability after sealing, and since it is an eco-friendly material substantially free of Pb (lead), there is no fear of exposure to environmental pollution.

The present invention is a sealing glass frit composition substantially free of lead (Pb), and is used for sealing flat display panels such as fluorescent display devices (VFDs), field emission displays (FEDs), plasma display panels (PDPs), and the like.

Existing sealing composition mainly contains lead-containing PbO-B ₂ O ₃ -SiO ₂ -based glass frit, and ceramic filler and lead-containing PbTiO ₃ were mainly used. In recent years, the use of lead leads to contamination of soil and water quality, and the situation is regulated worldwide. Therefore, research on lead-free glass frit compositions for sealing substantially free of lead has been actively conducted.

Among these compositions, P ₂ O ₅ -SnO / ZnO-based glass frit can be sealed at low temperature, but its chemical durability is weak and it is non-uniformly sealed at the time of secondary sealing because SnO of glass frit is reduced to Sn metal during burn out process of binder during primary sintering. In addition, there is a weak point that the adhesion between the glass and the glass, BaO-ZnO-B ₂ O ₃ glass frit also has a weak chemical durability, there is a limit to low temperature sealing, Bi ₂ O ₃ mainly in terms of chemical durability The glass frit has been studied.

However, since the Bi ₂ O ₃ -based glass frit is used for sealing a flat panel display panel, the glass frit itself is determined to at least 520 ° C. since the first sintering of the internal phosphor composition and the sealing composition is performed simultaneously for the process and cost reduction. These compositions should not be precipitated, but the above compositions cause partial crystals to be precipitated, causing the partial crystal parts not to re-melt during secondary low temperature (500 ° C or less) sealing firing, resulting in uneven sealing, which shortens the life span of the flat panel display panel. . In addition, simultaneous sintering with the phosphor composition at less than 520 ° C results in poor contrast due to the presence of carbon in the flat panel display panel due to the remaining binder in the phosphor composition, which causes durability and reliability problems of the flat panel display panel. Accordingly, the present invention solves the problems of the conventional lead-free glass frit composition for sealing and does not contain lead, and is a sealing composition containing no lead, which can be simultaneously sintered with the phosphor composition at 520 ° C. or lower, and can be sealed at a lower temperature and at the same time low temperature fluidity. By inventing this excellent lead-free frit composition for sealing, which has no problem of crystal precipitation and smaller thermal expansion coefficient, productivity and durability and reliability of a flat panel display panel manufacturing process can be improved.

The lead-free glass frit composition for sealing of the present invention can be co-sintered with the phosphor composition at a primary sintering temperature of 520 ° C. or lower, substantially free of lead, and 32 to 42 mol% of Bi ₂ O ₃ and 25 to 35 ZnO. 80 to 95% by weight of glass frit containing 22 to 28 mol% of mol% and B ₂ O ₃ and 5 to 20% by weight of low-expansion ceramic filler, and further comprising 0.5 to 5 mol% of SiO ₂ in the glass frit. It further comprises 0.5 to 5 mol% of at least one alkali metal oxide selected from Li ₂ O, Na ₂ O, K ₂ O and Cs ₂ O, and at least one transition metal oxide selected from CoO, CuO, NiO and MnO. It is a composition containing 0.5-4 mol% further.

Bi ₂ O ₃ is a material that replaces PbO and is an essential component for low melting of glass frit. If the content of Bi ₂ O ₃ is less than 32 mol%, the low melting of the glass frit is insufficient, which makes it difficult to serve as an encapsulating material. If the content of the Bi ₂ O ₃ exceeds 42 mol%, the melting coefficient of the glass frit is lower than that of the glass frit. The crystals precipitate at or below 520 ° C., making sealing difficult. Therefore, the content of Bi ₂ O ₃ in the glass frit is 32 to 42 mol%, more preferably 34 to 41 mol%, in the range without lower temperature sealing and crystal precipitation.

In addition, ZnO of the configuration of the glass frit is a necessary ingredient to screen low-melting glass frit with Bi ₂ O _3. When the content of ZnO is less than 25 mol%, it is difficult to increase the coefficient of thermal expansion and low temperature sealing of the glass frit at the time of sealing firing, and when it exceeds 35 mol%, the glass frit is easily crystallized during the sealing firing, making the sealing difficult. Thus ZnO in glass frit The content is in the range of 25 to 35 mol%, more preferably in the range of 27 to 33 mol%, with no lower temperature sealing and crystal precipitation.

In addition, B ₂ O ₃ in the composition of the glass frit is an essential component for forming a mesh of glass and suppressing crystallization of the glass during the primary sintering and the secondary sealing firing. If the content of B ₂ O ₃ is less than 22 mol%, there is no effect of inhibiting the crystals of the glass frit at the time of sealing firing, and if it exceeds 28 mol%, the melting of the glass frit is insufficient and the sealing becomes difficult. Therefore, the B ₂ O ₃ content in the glass frit is in the range of 22 to 28 mol%, more preferably 23 to 26 mol%, in the range without lower temperature sealing and crystal precipitation.

In addition, SiO ₂ in the composition of the glass frit is an essential component for improving the chemical durability of the glass and slightly suppressing the crystal. If the content of SiO ₂ is less than 0.5 mol%, there is no effect of inhibiting the crystals of the glass frit at the time of sealing firing, and if it exceeds 5 mol%, the softening point of the glass increases, making it difficult to seal at low temperatures. In the glass frit, the SiO ₂ content is in the range of 0.5 to 5 mol%, more preferably 1.5 to 4.5 mol%, in the range of lower temperature sealing and no crystal precipitation.

The glass frit has a limitation in suppressing the low temperature sealing and chemical durability and the crystal of glass with only Bi ₂ O ₃ -B ₂ O ₃ -ZnO-SiO ₂ 4 components. Therefore, it is necessary to further contain at least one alkali metal oxide selected from Li ₂ O, Na ₂ O, K ₂ O and Cs ₂ O and at least one transition metal oxide selected from CoO, CuO, NiO and MnO.

The at least one alkali metal oxide selected from Li ₂ O, Na ₂ O, K ₂ O and Cs ₂ O is essential for low melting of glass frit and is essential for inhibiting crystallization, but it greatly improves the coefficient of thermal expansion. Be careful. Therefore, the alkali metal oxide should be included in the range of 0.5 to 5 mol%, more preferably in the range of 2 to 4 mol%.

At least one transition metal oxide selected from CoO, CuO, NiO, and MnO promotes the melting of the glass frit to give structural stability to the glass, and suppresses crystallization of the glass frit to increase the crystal precipitation temperature. Therefore, the transition metal oxide should be included in the range of 0.5 to 4 mol%, more preferably in the range of 1 to 2.5 mol%.

The alkali metal oxide and the transition metal oxide must be included together, and the molar ratio of the alkali metal oxide and the transition metal oxide is preferably 1: 1 to 3: 1. If the alkali metal oxide is less than 1 mole based on 1 mole of the transition metal oxide, low temperature fluidity is poor and low temperature sealing becomes difficult. If the alkali metal oxide exceeds 3 moles, the sealing is caused by an increase in the glass frit coefficient of thermal expansion. Thermal stress occurs during firing, resulting in durability and reliability problems, and there is a problem in that crystals are precipitated at less than 520 ° C.

In addition, the sum of the alkali metal oxide and the transition metal oxide is preferably 3 to 6 mol% based on the total glass frit. When the sum of alkali metal oxide and transition metal oxide is less than 3 mol%, low temperature fluidity is poor, and low temperature sealing is difficult, and when it exceeds 6 mol%, thermal stress occurs during sealing firing due to an increase in coefficient of thermal expansion. A problem arises.

In addition, the glass frit may further include 0.1-6 mol% of BaO and 0.1-5 mol% of Al ₂ O ₃ to prevent low temperature sealing and crystal precipitation.

The coefficient of thermal expansion of the glass frit is preferably 120 × 10 ⁻⁷ / ° C. or less, more preferably 110 × 10 ⁻⁷ / ° C. or less. More than that is possible, but in order to be used as sealing composition, more ceramic filler should be included to make the coefficient of thermal expansion similar to or lower than the coefficient of thermal expansion of flat panel display panel glass. Becomes difficult.

The softening point of the glass frit (Td: softening point measured by a dilatometer) is preferably 400 ° C or lower. If the softening point of the glass frit exceeds 400 ℃, the low-expansion ceramic filler should contain 5 wt% or less of the lead-free glass frit composition for sealing in order to obtain a desired low temperature fluidity. Inconsistent with the coefficient of thermal expansion of panel glass, thermal stress is generated, resulting in durability and reliability problems.

It is preferable to contain 5-20 weight% of low-expansion ceramic filler in the lead-free glass frit composition for sealing. Here, the low-expansion ceramic filler is characterized in that the thermal expansion coefficient of at least one selected from the group consisting of cordierite (2MgO · 2Al ₂ O ₃ · 5SiO ₂ ) and zircon (ZrSiO ₄ ), which is significantly lower than the glass frit, If the sealing glass frit composition is less than 5% by weight, the thermal expansion coefficient is higher than the thermal expansion coefficient of the flat panel display panel glass, and thermal stress occurs during sealing firing, and if it exceeds 20% by weight, the softening point (Td: Dilatometer measurement softening point) is 400 ° C. This makes it more difficult to seal at a lower temperature due to the decrease in low temperature fluidity. Therefore, the content of the ceramic filler is preferably 5 to 20% by weight, more preferably 8 to 12% by weight.

In addition, the thermal expansion coefficient of the lead-free glass frit composition for sealing including the glass frit and the low-expansion ceramic filler is preferably in the range of 70 to 82 × 10 ⁻⁷ / ° C., and the softening point (Td: Dilatometer measurement softening point) is 400 ° C. or less. More preferably, the coefficient of thermal expansion is 70 to 80 × 10 ⁻⁷ / ° C., most preferably 75 to 80 × 10 ⁻⁷ / ° C., and the softening point (Td: Dilatometer measurement softening point) is more preferably 390 ° C. or less.

The glass frit (powder) of the present invention and the lead-free glass frit composition for sealing are not precipitated when they are maintained at a temperature to be sintered at a temperature of 10 ° C./min up to 520 ° C. at a temperature of sintering temperature of 520 ° C. or less for 18 minutes. As a glass frit having a composition which does not have a composition, the sealing glass frit composition alone or the sealing glass frit composition and the phosphor composition may be simultaneously fired at 520 ° C. or lower during the first sintering, thereby reducing the production cost according to the shortening of the manufacturing process. Therefore, in order to apply to sealing of various types of flat panel display panels, it is preferable that the lead-free glass frit composition does not crystallize at 520 degreeC.

Hereinafter, the present invention will be described in detail with reference to Examples and Experimental Examples. However, the following Examples and Experimental Examples are merely illustrative of the present invention, but the content of the present invention is not limited thereto.

The raw materials were combined and mixed so as to form the chemical compositions shown in Table 1 below, and then the mixed raw materials were placed in a melting crucible to produce glass through melting, clarification, and cooling at 1100 ° C. for 30 minutes. After the obtained glass was put into a ball mill and subjected to dry grinding, glass frit powder was obtained through a 100 µm sieve. Laser system using a scattering type particle size distribution of the average particle diameter of a glass frit powder, measured by the values of D ₅₀ of the volume distribution mode was 8 ~ 12㎛. The glass frit powder and the low-expansion ceramic filler [Cordierite (2MgO.2Al ₂ O ₃ .5SiO ₂ ), Zircon (ZrSiO ₄ )] were mixed at the ratio shown in Table 1 to obtain a sealing composition powder. The glass transition point, the softening point, the coefficient of thermal expansion, and the flow button for each of the glass frit powders and the sealing composition powders obtained at this time were measured and shown in Table 1 below.

(1) coefficient of thermal expansion, transition point, softening point

The glass frit and the sealing composition powder were press-molded at the sealing temperature shown in Table 1, and then cut into a 5 x 5 x 40 mm fired body and cut at room temperature to 5 ° C / min using a dilatometer. The thermal expansion coefficient was calculated from the curve obtained when the temperature was raised to around 30 to 300 ° C, and the sudden rise point of the obtained curve was determined as the transition point and the point where the curve rose and fell as the softening point (Td · Ts: softening point on the dilatometer).

(2) Flow Button (F / B)

According to ASTM C 374-70 (Standard Test Method for Fusion Flow of Porcelain Enamel Frits), 3.5 ± 0.05 g of glass frit and sealing composition powder were press-molded into a 12 mm-diameter cylindrical cylinder on top of soda-lime glass. It measured and obtained the maximum external shape of the fired body obtained when it heated up at / min and hold | maintained for 18 minutes at 485 degreeC, 500 degreeC, or 520 degreeC fixed primary sintering temperature. Furthermore, crystal precipitation oil (Y) and no (N) by the surface observation of this sintered compact were confirmed.

division
Manufacturing example a b c d e f g h i j k Bi ₂ O ₃ (mol%) 34.0 39.0 37.0 40.0 40.0 40.5 40.0 40.0 41.5 43.0 44.5 B ₂ O ₃ (mol%) 22.0 22.0 21.5 24.0 23.5 24.5 24.0 24.0 21.0 21.5 22.0 ZnO (mol%) 34.0 31.0 38.0 28.0 28.0 29.0 28.0 28.0 29.0 26.5 24.5 BaO (mol%) - 3.5 0.5 - - - - - - - - SiO ₂ (mol%) 2.6 3.0 - 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Al ₂ O ₃ (mol%) 1.4 1.5 1.0 0.5 0.5 0.5 - - - - - Na ₂ O (mol%) 5.0 - 2.0 4.0 2.5 3.5 3.5 3.5 3.5 4.0 4.0 CoO (mol%) 1.0 - - 1.5 3.5 - 2.5 - 3.0 3.0 3.0 NiO (mol%) - - - - - - - 2.5 - - - CTE (× 10 ^-7 / ℃) 113 103 104 111 105 104 109 108 113 115 114 Transition point (℃) 360 370 360 353 375 360 355 355 340 330 338 Softening point (℃) 390 405 380 380 410 380 380 380 360 355 365 Crystal Formation (500 ℃) N N N N N N N N N N Y Crystal Formation (520 ℃) Y Y Y N N Y N N Y Y Y F / B at 520 ℃ (mm) 20.5 19.8 20.1 22.8 20.8 20.4 23.8 23.8 20.5 20.3 20.0

division
Example Comparative example One 2 3 One 2 3 4 5 6 7 8 Glass
Frit Kinds d g h a b c c e h j j weight% 88 88 90 90 90 92 92 90 90 90 90 filler Cordierite (% by weight) 8 8 10 10 10 8 8 10 10 10 10 Zircon (% by weight) 4 4 - - - - - - - - - Condition Primary sintering temperature (℃) 520 520 520 520 520 500 520 520 500 500 520 Sealing temperature (℃) 460 450 450 470 485 470 470 490 450 440 440 characteristic CTE (× 10 ^-7 / ℃) 80.3 80.5 79.5 82.5 81.5 80.3 80.3 81.7 79.5 81.2 81.2 Transition point (℃) 350 355 350 360 370 365 365 375 350 335 335 Softening point (℃) 390 378 376 390 410 390 390 415 376 365 365 F / B at 485 ℃ (mm) 19.3 19.7 19.7 - - - - 17.8 - - - F / B at 500 ℃ (mm) - - - - - 19.6 - - 20.5 20.5 - F / B at 520 ℃ (mm) 21.5 22.0 22.0 18.7 18.5 - 19.1 20.0 - - 19.7 Crystal Formation
(At 1st sintering temperature) N N N Y Y N Y N N N Y

Preparation Examples b, c and f are compositions containing no one or more of alkali metal oxides and transition metal oxides, wherein no crystals are formed at 500 ° C., but crystals are formed at 520 ° C., and the flow button is less than 21, in particular. Preparation Example b was also very unsuitable for use in sealing compositions because the softening point was very high.

Preparation Examples a, i, j and k are glass frits containing both alkali metal oxides and transition metal oxides, but in Preparation Example a, the mol% of the alkali metal oxide is 5 times the transition metal oxide, and Preparation Examples i, j and k Is a composition in which the sum of the alkali metal oxide and the transition metal oxide exceeds 6 mol%, and in particular, Preparation Examples j and k have a composition in which Bi ₂ O ₃ mol% exceeds 42 mol%, and crystals are formed at 520 ° C., In particular, the preparation k is also produced crystals even at 500 ℃, the flow button is very low to 20.0 ~ 20.5 is not suitable for use as a sealing composition because it is not remelted by the partial crystal during sealing.

Preparation examples d, e, g and h are all crystals are not produced at 520 ℃, but Preparation e has a low flow button of 20.8 is difficult to seal at low temperature, Preparation examples d, g, and h is 22.8 or more, so at 520 ℃ It was expected that there would be no problem with co-firing with the phosphor composition.

Example 1 is the glass frit of Preparation Example d, Example 2 is the glass frit of Preparation Example g, Example 3 is using the glass frit of Preparation Example h, Example 3 has a coefficient of thermal expansion of 79.5 × 10 ^-7 / ℃, Advantages 350 ℃, softening point 376 ℃, Flow Button 22.0mm and the minimum sealing temperature of 450 ℃ or less, the most excellent among them was satisfied with the glass frit for sealing flat panel display panel.

On the other hand, Comparative Examples 1, 2, 3, 4, 7 and 8 contained glass frit that crystals were not produced at 500 ° C. but crystals were formed at 520 ° C., and thus, among the sealing compositions in which low-expansion ceramic fillers were mixed. In Examples 3 and 7, no crystals were formed at the primary sintering temperature of 500 ° C. However, when primary sintering at 500 ° C resulted in the binder being not completely burned when co-fired with the phosphor composition, the inevitably adversely affects the contrast and durability of the panel. In Comparative Examples 1, 2, 4, and 8, crystals were formed at 520 ° C., and all were not suitable as sealing compositions.

In Comparative Example 5, the glass frit of Preparation Example e was used, and crystals were not produced at 520 ° C., but the softening point was high, so that the flow buttons were very low at 17.8 and 20.0 at 485 ° C. and 520 ° C., respectively.

In addition, comparing Comparative Examples 3 and 4 and Comparative Examples 7 and 8, when the sintering temperature was changed to 500 ° C and 520 ° C in the same composition, the flow buttons were compared to 500 ° C rather than 520 ° C. It was shown that the high value, the sintering temperature at 520 ℃ caused the shrinkage due to the crystal growth, the flow button characteristics were estimated to be rather poor than at 500 ℃.

On the other hand, when comparing the Example 3 and Comparative Example 6, when the sealing composition is manufactured by only the first sintering temperature in the same composition, there is no crystal precipitation at 520 ℃, the flow button characteristics are excellent at 22.0 at 520 ℃ than 500 ℃ I could see that.

Claims (9)

80-95% by weight of glass frit and 32-42 mol% of Bi ₂ O ₃ , 25-35 mol% of ZnO and 22-28 mol% of B ₂ O ₃ without lead (Pb) and low-expansion ceramic filler 5 In the lead-free glass frit composition for sealing containing 20% by weight, The glass frit further includes 0.5 to 5 mol% of SiO ₂ , and further includes 0.5 to 5 mol% of at least one alkali metal oxide selected from Li ₂ O, Na ₂ O, K ₂ O, and Cs ₂ O, Further comprising 0.5 to 4 mol% of at least one transition metal oxide selected from CoO, CuO, NiO and MnO, The molar ratio of the alkali metal oxide and the transition metal oxide is 1: 1 to 3: 1, the sum of the alkali metal oxide and the transition metal oxide is 3 to 6 mol%, The glass frit does not precipitate crystals when sintered at 520 ° C., is sealed at 490 ° C. or less, and has a softening point (Td: Dilatometer measurement softening point) of 400 ° C. or less. delete delete The lead-free glass frit composition of claim 1, wherein the glass frit further comprises 0.1-6 mol% of BaO or 0.1-5 mol% of Al ₂ O ₃ . delete The lead-free glass frit composition for sealing a flat panel display panel according to claim 1, wherein the phosphor composition can be co-fired at 520 캜 or lower. delete The lead-free glass frit composition for sealing a flat panel display panel according to claim 1 or 4, wherein the low-expansion ceramic filler is at least one selected from cordierite and zircon. [Claim 10] The flat panel display according to claim 8, wherein the sealing glass frit composition in which the glass frit and the low-expansion ceramic filler are mixed has a coefficient of thermal expansion in the range of 70 to 82 x 10 ^-7 / ° C at 30 to 300 ° C. Lead-free glass frit composition for panel sealing.